The discretionary part of my system

I do not blindly follow the signals my trading software gives me. The chart of Travis Perkins (LSE: TPK) below gives a good example.

A sell signal was given near the end of April, however I did not enter the trade. The reason is that the previous low from mid March could act as support (I've drawn a red arrow on the chart to show this level). As you can see, the share price did indeed bounce off that level. I would have waited for that support level to be broken before entering the position.